This invention relates to a respiration monitoring apparatus applied to a living body fitted with an artificial respirator.
In recent years, a noticeable progress has been achieved in managements with artificial ventilation, enabling the operation of the circulatory, respiratory or central nervous system which has hitherto presented difficulties, and making great contribution to the improvement of medical treatment. The development of an artificial respirator plays an important role in promoting this development. What is most important in monitoring respiration by applying an artificial respirator is the detection of a spontaneous respiration. Generally, the artificial respirator is removed only after an assisted respiration based on a spontaneous respiration and the operation of the artificial respirator has continued for a prescribed length of time. The timing in which the artificial respirator is taken off largely affects the subsequent convalescent condition of a patient. When respiration is monitored, a parameter of ventilation dynamics such as lung compliance has to be processed by varying algorithm according to whether or not a patient has commenced spontaneous respiration. Another important factor is to examine whether an artificial respirator is satisfactorily fitted to a patient, or whether the operation of the artificial respirator and a spontaneous respiration are exactly synchronized with each other during the period of the assisted respiration.
Hitherto, however, the judgment of these facts has mainly relied on the naked eye observation of a patient's chest wall by a physician or nurse. In other words, the above-mentioned judgment has failed to be objectively carried out, sometimes adversely affecting a patient's convalescent condition.